Browsing Research Articles (Statistics & Population Studies) by Title
Now showing items 33-52 of 162
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Evidence for rapid evolution of periodic variations in an ultracool dwarf
(Oxford University Press, 2006)The results of three short photometric monitoring runs on the L0 dwarf 2MASS J06050196−2342270, during three consecutive nights, are presented. The observations show the persistent presence of a 2.4-h period, with an IC ... -
Examining inequality of opportunity in the use of maternal and reproductive health interventions in Sierra Leone
(Oxford University Press, 2020)Poor countries, such as Sierra Leone, often have poor health outcomes, whereby the majority of the population cannot access lifesaving health services. Access to, and use of, maternal and reproductive health services is ... -
An exploratory look at associated factors of poverty on educational attainment in Africa and in-depth multilevel modelling for Namibia.
(BER, 2013)This study examines several indicator variables related to education and poverty in Africa from the Demographic and Health Surveys (DHS). Many have described income and education as one of the fundamental determinants ... -
An extensive search for rapid optical variability in ultracool dwarfs
(Oxford University Press, 2013)In this paper, a summary of optical time-series photometry of 125 ultracool dwarfs is given. The observing strategy was to monitor each object continuously for 2–3 h in order to ascertain whether itwas rapidly variable. ... -
Factors affecting the enrolment rate of students in Higher Education Institutions in the Gauteng province, South Africa
(SAGE, 2018)The purpose of this research is to investigate and analyse higher education institutions' enrolment and drop-out rates within the Gauteng province, South Africa. Large-scale secondary data from the General Household ... -
Factors associated with antiretroviral treatment failure among people living with HIV on antiretroviral therapy in resource- poor settings: a systematic review and metaanalysis
(BMC, 2020)Background: Despite the increase in the number of people accessing antiretroviral therapy (ART), there is limited data regarding treatment failure and its related factors among HIV-positive individuals enrolled in HIV care ... -
Factors associated with mothers’ health care‑seeking behaviours for childhood fever in Burkina Faso: Findings from repeated cross‑sectional household surveys
(BMC, 2022)Fever is one of the most frequent reasons for paediatric consultations in Burkina Faso, but health careseeking behaviours and the factors associated with health care-seeking in the event of childhood fever are poorly documented. ... -
Factors associated with patellofemoral pain in recreational road cyclists: A cross-sectional study in 59953 cyclists – SAFER XXXIII
(Elsevier, 2023)Patellofemoral pain (PFP) is a common cycling-related injury, and independent factors need to be identified to enable effective injury prevention strategies. We aim to determine factors associated with PFP in cyclists ... -
Fitting power-law distributions to data with measurement errors
(Oxford University Press, 2009)If X, which follows a power-law distribution, is observed subject to Gaussian measurement error e, thenX+e is distributed as the convolution of the power-lawand Gaussian distributions. Maximum-likelihood estimation of ... -
Fitting sinusoids to observations of rotating spotted stars
(Oxford University Press, 2007)It is assumed that K blocks (e.g. seasons) of observations are available, and the parameters characterizing a fixed-frequency sinusoidal variability (mean light level, amplitude, phase) are constant within each of the ... -
The “four sigma” limit for significant periodicities
(Springer Verlag, 2010)Most of the pulsations which have been observed in sdB stars have very low amplitudes. Detection of modes from photometric observations is usually performed by noting the most prominent peaks in a periodogram or, ... -
Further observations of Hipparcos red stars and standards for UBV(RI)C photometry
(Oxford University Press, 2007)We present homogeneous and standardized UBV(RI)C JHK photometry for over 100 M stars selected from an earlier paper on the basis of apparent photometric constancy. L photometry has been obtained for stars brighter than ... -
Global warming and psychotraumatology of natural disasters: the case of the deadly rains and floods of April 2022 in South Africa
(Annales Médico-psychologiques, revue psychiatrique, 2023)Climate change and global warming have led to an increased incidence of flooding across the world. Against the backdrop of the recent devastating floods in the Kwazulu-Natal province of South Africa, this paper explores ... -
HE 0230–4323: An unusual pulsating hot subdwarf star
(Oxford University Press, 2007)HE 0230−4323 is a known binary, consisting of a subdwarf star and a companion which is not observable in the optical. Photometric measurements reported in this paper have shown it to be both a reflection-effect and a ... -
HE 0230−4323 revisited: a new rapidly pulsating sdB star
(Oxford University Press, 2010)HE 0230−4323 is a hot sdB star in a binary system. An earlier work demonstrated that the light curve of the system shows a strong (∼4 per cent) reflection effect and also appears to exhibit photometric variations of the ... -
HE0230–4323: an unusual pulsating hot subdwarf star
(Oxford University Press, 2007)HE 0230−4323 is a known binary, consisting of a subdwarf star and a companion which is not observable in the optical. Photometric measurements reported in this paper have shown it to be both a reflection-effect and a ... -
Health trends, inequalities and opportunities in South Africa’s provinces, 1990–2019: Findings from the Global burden of disease 2019 Study
(BMJ Publishing Group, 2022)Over the last 30 years, South Africa has experienced four ’colliding epidemics’ of HIV and tuberculosis, chronic illness and mental health, injury and violence, and maternal, neonatal, and child mortality, which have ... -
HerMES: Candidate gravitationally lensed galaxies and lensing statistics at submillimeter wavelengths
(American Astronomical Society, 2013)Gravitational lensing increases the angular size and integrated flux of affected sources. It is exploited to investigate the mass distribution of the foreground lensing structures and the properties of the background lensed ... -
Hermes: Cosmic infrared background anisotropies and the clustering of dusty star-forming galaxies
(American Astronomical Society, 2013)Star formation is well traced by dust, which absorbs the UV/optical light produced by young stars in actively starforming regions and re-emits the energy in the far-infrared/ submillimeter (FIR/submm; e.g., Savage & ... -
HerMES: The contribution to the cosmic infrared background from galaxies selected by mass and redshift
(American Astronomical Society, 2013)The cosmic infrared background (CIB), discovered in Far Infrared Absolute Spectrophotometer (FIRAS) data from the Cosmic Background Explorer (COBE; Puget et al. 1996; Fixsen et al. 1998), originates from thermal ...
